Design Docs at Google

"Besides the original documentation of a software design, design docs fulfill the following functions in the software development lifecycle:

"Design docs are informal documents and thus don’t follow a strict guideline for their content. Rule #1 is: Write them in whatever form makes the most sense for the particular project. Having said that, a certain structure has established itself as really useful:

The length of a design doc Design docs should be sufficiently detailed but short enough to actually be read by busy people. The sweet spot for a larger project seems to be around 10-20ish pages. If you get way beyond that, it might make sense to split up the problem into more manageable sub problems. It should also be noted that it is absolutely possible to write a 1-3 page “mini design doc”. This is especially helpful for incremental improvements or sub tasks in an agile project–you still do all the same steps as for a longer doc, just keep things more terse and focused on a limited problem set.


The steps in the lifecycle of a design document are:

Tags: architecture   design   reading  

Last modified 06 April 2022